linux/sound/usb/bcd2000/bcd2000.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Behringer BCD2000 driver
   4 *
   5 *   Copyright (C) 2014 Mario Kicherer (dev@kicherer.org)
   6 */
   7
   8#include <linux/kernel.h>
   9#include <linux/errno.h>
  10#include <linux/init.h>
  11#include <linux/slab.h>
  12#include <linux/module.h>
  13#include <linux/bitmap.h>
  14#include <linux/usb.h>
  15#include <linux/usb/audio.h>
  16#include <sound/core.h>
  17#include <sound/initval.h>
  18#include <sound/rawmidi.h>
  19
  20#define PREFIX "snd-bcd2000: "
  21#define BUFSIZE 64
  22
  23static const struct usb_device_id id_table[] = {
  24        { USB_DEVICE(0x1397, 0x00bd) },
  25        { },
  26};
  27
  28static const unsigned char device_cmd_prefix[] = {0x03, 0x00};
  29
  30static const unsigned char bcd2000_init_sequence[] = {
  31        0x07, 0x00, 0x00, 0x00, 0x78, 0x48, 0x1c, 0x81,
  32        0xc4, 0x00, 0x00, 0x00, 0x5e, 0x53, 0x4a, 0xf7,
  33        0x18, 0xfa, 0x11, 0xff, 0x6c, 0xf3, 0x90, 0xff,
  34        0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
  35        0x18, 0xfa, 0x11, 0xff, 0x14, 0x00, 0x00, 0x00,
  36        0x00, 0x00, 0x00, 0x00, 0xf2, 0x34, 0x4a, 0xf7,
  37        0x18, 0xfa, 0x11, 0xff
  38};
  39
  40struct bcd2000 {
  41        struct usb_device *dev;
  42        struct snd_card *card;
  43        struct usb_interface *intf;
  44        int card_index;
  45
  46        int midi_out_active;
  47        struct snd_rawmidi *rmidi;
  48        struct snd_rawmidi_substream *midi_receive_substream;
  49        struct snd_rawmidi_substream *midi_out_substream;
  50
  51        unsigned char midi_in_buf[BUFSIZE];
  52        unsigned char midi_out_buf[BUFSIZE];
  53
  54        struct urb *midi_out_urb;
  55        struct urb *midi_in_urb;
  56
  57        struct usb_anchor anchor;
  58};
  59
  60static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
  61static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
  62
  63static DEFINE_MUTEX(devices_mutex);
  64static DECLARE_BITMAP(devices_used, SNDRV_CARDS);
  65static struct usb_driver bcd2000_driver;
  66
  67#ifdef CONFIG_SND_DEBUG
  68static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len)
  69{
  70        print_hex_dump(KERN_DEBUG, prefix,
  71                        DUMP_PREFIX_NONE, 16, 1,
  72                        buf, len, false);
  73}
  74#else
  75static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len) {}
  76#endif
  77
  78static int bcd2000_midi_input_open(struct snd_rawmidi_substream *substream)
  79{
  80        return 0;
  81}
  82
  83static int bcd2000_midi_input_close(struct snd_rawmidi_substream *substream)
  84{
  85        return 0;
  86}
  87
  88/* (de)register midi substream from client */
  89static void bcd2000_midi_input_trigger(struct snd_rawmidi_substream *substream,
  90                                                int up)
  91{
  92        struct bcd2000 *bcd2k = substream->rmidi->private_data;
  93        bcd2k->midi_receive_substream = up ? substream : NULL;
  94}
  95
  96static void bcd2000_midi_handle_input(struct bcd2000 *bcd2k,
  97                                const unsigned char *buf, unsigned int buf_len)
  98{
  99        unsigned int payload_length, tocopy;
 100        struct snd_rawmidi_substream *midi_receive_substream;
 101
 102        midi_receive_substream = READ_ONCE(bcd2k->midi_receive_substream);
 103        if (!midi_receive_substream)
 104                return;
 105
 106        bcd2000_dump_buffer(PREFIX "received from device: ", buf, buf_len);
 107
 108        if (buf_len < 2)
 109                return;
 110
 111        payload_length = buf[0];
 112
 113        /* ignore packets without payload */
 114        if (payload_length == 0)
 115                return;
 116
 117        tocopy = min(payload_length, buf_len-1);
 118
 119        bcd2000_dump_buffer(PREFIX "sending to userspace: ",
 120                                        &buf[1], tocopy);
 121
 122        snd_rawmidi_receive(midi_receive_substream,
 123                                        &buf[1], tocopy);
 124}
 125
 126static void bcd2000_midi_send(struct bcd2000 *bcd2k)
 127{
 128        int len, ret;
 129        struct snd_rawmidi_substream *midi_out_substream;
 130
 131        BUILD_BUG_ON(sizeof(device_cmd_prefix) >= BUFSIZE);
 132
 133        midi_out_substream = READ_ONCE(bcd2k->midi_out_substream);
 134        if (!midi_out_substream)
 135                return;
 136
 137        /* copy command prefix bytes */
 138        memcpy(bcd2k->midi_out_buf, device_cmd_prefix,
 139                sizeof(device_cmd_prefix));
 140
 141        /*
 142         * get MIDI packet and leave space for command prefix
 143         * and payload length
 144         */
 145        len = snd_rawmidi_transmit(midi_out_substream,
 146                                bcd2k->midi_out_buf + 3, BUFSIZE - 3);
 147
 148        if (len < 0)
 149                dev_err(&bcd2k->dev->dev, "%s: snd_rawmidi_transmit error %d\n",
 150                                __func__, len);
 151
 152        if (len <= 0)
 153                return;
 154
 155        /* set payload length */
 156        bcd2k->midi_out_buf[2] = len;
 157        bcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;
 158
 159        bcd2000_dump_buffer(PREFIX "sending to device: ",
 160                        bcd2k->midi_out_buf, len+3);
 161
 162        /* send packet to the BCD2000 */
 163        ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);
 164        if (ret < 0)
 165                dev_err(&bcd2k->dev->dev, PREFIX
 166                        "%s (%p): usb_submit_urb() failed, ret=%d, len=%d\n",
 167                        __func__, midi_out_substream, ret, len);
 168        else
 169                bcd2k->midi_out_active = 1;
 170}
 171
 172static int bcd2000_midi_output_open(struct snd_rawmidi_substream *substream)
 173{
 174        return 0;
 175}
 176
 177static int bcd2000_midi_output_close(struct snd_rawmidi_substream *substream)
 178{
 179        struct bcd2000 *bcd2k = substream->rmidi->private_data;
 180
 181        if (bcd2k->midi_out_active) {
 182                usb_kill_urb(bcd2k->midi_out_urb);
 183                bcd2k->midi_out_active = 0;
 184        }
 185
 186        return 0;
 187}
 188
 189/* (de)register midi substream from client */
 190static void bcd2000_midi_output_trigger(struct snd_rawmidi_substream *substream,
 191                                                int up)
 192{
 193        struct bcd2000 *bcd2k = substream->rmidi->private_data;
 194
 195        if (up) {
 196                bcd2k->midi_out_substream = substream;
 197                /* check if there is data userspace wants to send */
 198                if (!bcd2k->midi_out_active)
 199                        bcd2000_midi_send(bcd2k);
 200        } else {
 201                bcd2k->midi_out_substream = NULL;
 202        }
 203}
 204
 205static void bcd2000_output_complete(struct urb *urb)
 206{
 207        struct bcd2000 *bcd2k = urb->context;
 208
 209        bcd2k->midi_out_active = 0;
 210
 211        if (urb->status)
 212                dev_warn(&urb->dev->dev,
 213                        PREFIX "output urb->status: %d\n", urb->status);
 214
 215        if (urb->status == -ESHUTDOWN)
 216                return;
 217
 218        /* check if there is more data userspace wants to send */
 219        bcd2000_midi_send(bcd2k);
 220}
 221
 222static void bcd2000_input_complete(struct urb *urb)
 223{
 224        int ret;
 225        struct bcd2000 *bcd2k = urb->context;
 226
 227        if (urb->status)
 228                dev_warn(&urb->dev->dev,
 229                        PREFIX "input urb->status: %i\n", urb->status);
 230
 231        if (!bcd2k || urb->status == -ESHUTDOWN)
 232                return;
 233
 234        if (urb->actual_length > 0)
 235                bcd2000_midi_handle_input(bcd2k, urb->transfer_buffer,
 236                                        urb->actual_length);
 237
 238        /* return URB to device */
 239        ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_ATOMIC);
 240        if (ret < 0)
 241                dev_err(&bcd2k->dev->dev, PREFIX
 242                        "%s: usb_submit_urb() failed, ret=%d\n",
 243                        __func__, ret);
 244}
 245
 246static const struct snd_rawmidi_ops bcd2000_midi_output = {
 247        .open =    bcd2000_midi_output_open,
 248        .close =   bcd2000_midi_output_close,
 249        .trigger = bcd2000_midi_output_trigger,
 250};
 251
 252static const struct snd_rawmidi_ops bcd2000_midi_input = {
 253        .open =    bcd2000_midi_input_open,
 254        .close =   bcd2000_midi_input_close,
 255        .trigger = bcd2000_midi_input_trigger,
 256};
 257
 258static void bcd2000_init_device(struct bcd2000 *bcd2k)
 259{
 260        int ret;
 261
 262        init_usb_anchor(&bcd2k->anchor);
 263        usb_anchor_urb(bcd2k->midi_out_urb, &bcd2k->anchor);
 264        usb_anchor_urb(bcd2k->midi_in_urb, &bcd2k->anchor);
 265
 266        /* copy init sequence into buffer */
 267        memcpy(bcd2k->midi_out_buf, bcd2000_init_sequence, 52);
 268        bcd2k->midi_out_urb->transfer_buffer_length = 52;
 269
 270        /* submit sequence */
 271        ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_KERNEL);
 272        if (ret < 0)
 273                dev_err(&bcd2k->dev->dev, PREFIX
 274                        "%s: usb_submit_urb() out failed, ret=%d: ",
 275                        __func__, ret);
 276        else
 277                bcd2k->midi_out_active = 1;
 278
 279        /* pass URB to device to enable button and controller events */
 280        ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_KERNEL);
 281        if (ret < 0)
 282                dev_err(&bcd2k->dev->dev, PREFIX
 283                        "%s: usb_submit_urb() in failed, ret=%d: ",
 284                        __func__, ret);
 285
 286        /* ensure initialization is finished */
 287        usb_wait_anchor_empty_timeout(&bcd2k->anchor, 1000);
 288}
 289
 290static int bcd2000_init_midi(struct bcd2000 *bcd2k)
 291{
 292        int ret;
 293        struct snd_rawmidi *rmidi;
 294
 295        ret = snd_rawmidi_new(bcd2k->card, bcd2k->card->shortname, 0,
 296                                        1, /* output */
 297                                        1, /* input */
 298                                        &rmidi);
 299
 300        if (ret < 0)
 301                return ret;
 302
 303        strlcpy(rmidi->name, bcd2k->card->shortname, sizeof(rmidi->name));
 304
 305        rmidi->info_flags = SNDRV_RAWMIDI_INFO_DUPLEX;
 306        rmidi->private_data = bcd2k;
 307
 308        rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
 309        snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 310                                        &bcd2000_midi_output);
 311
 312        rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
 313        snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 314                                        &bcd2000_midi_input);
 315
 316        bcd2k->rmidi = rmidi;
 317
 318        bcd2k->midi_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 319        bcd2k->midi_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 320
 321        if (!bcd2k->midi_in_urb || !bcd2k->midi_out_urb) {
 322                dev_err(&bcd2k->dev->dev, PREFIX "usb_alloc_urb failed\n");
 323                return -ENOMEM;
 324        }
 325
 326        usb_fill_int_urb(bcd2k->midi_in_urb, bcd2k->dev,
 327                                usb_rcvintpipe(bcd2k->dev, 0x81),
 328                                bcd2k->midi_in_buf, BUFSIZE,
 329                                bcd2000_input_complete, bcd2k, 1);
 330
 331        usb_fill_int_urb(bcd2k->midi_out_urb, bcd2k->dev,
 332                                usb_sndintpipe(bcd2k->dev, 0x1),
 333                                bcd2k->midi_out_buf, BUFSIZE,
 334                                bcd2000_output_complete, bcd2k, 1);
 335
 336        /* sanity checks of EPs before actually submitting */
 337        if (usb_urb_ep_type_check(bcd2k->midi_in_urb) ||
 338            usb_urb_ep_type_check(bcd2k->midi_out_urb)) {
 339                dev_err(&bcd2k->dev->dev, "invalid MIDI EP\n");
 340                return -EINVAL;
 341        }
 342
 343        bcd2000_init_device(bcd2k);
 344
 345        return 0;
 346}
 347
 348static void bcd2000_free_usb_related_resources(struct bcd2000 *bcd2k,
 349                                                struct usb_interface *interface)
 350{
 351        /* usb_kill_urb not necessary, urb is aborted automatically */
 352
 353        usb_free_urb(bcd2k->midi_out_urb);
 354        usb_free_urb(bcd2k->midi_in_urb);
 355
 356        if (bcd2k->intf) {
 357                usb_set_intfdata(bcd2k->intf, NULL);
 358                bcd2k->intf = NULL;
 359        }
 360}
 361
 362static int bcd2000_probe(struct usb_interface *interface,
 363                                const struct usb_device_id *usb_id)
 364{
 365        struct snd_card *card;
 366        struct bcd2000 *bcd2k;
 367        unsigned int card_index;
 368        char usb_path[32];
 369        int err;
 370
 371        mutex_lock(&devices_mutex);
 372
 373        for (card_index = 0; card_index < SNDRV_CARDS; ++card_index)
 374                if (!test_bit(card_index, devices_used))
 375                        break;
 376
 377        if (card_index >= SNDRV_CARDS) {
 378                mutex_unlock(&devices_mutex);
 379                return -ENOENT;
 380        }
 381
 382        err = snd_card_new(&interface->dev, index[card_index], id[card_index],
 383                        THIS_MODULE, sizeof(*bcd2k), &card);
 384        if (err < 0) {
 385                mutex_unlock(&devices_mutex);
 386                return err;
 387        }
 388
 389        bcd2k = card->private_data;
 390        bcd2k->dev = interface_to_usbdev(interface);
 391        bcd2k->card = card;
 392        bcd2k->card_index = card_index;
 393        bcd2k->intf = interface;
 394
 395        snd_card_set_dev(card, &interface->dev);
 396
 397        strncpy(card->driver, "snd-bcd2000", sizeof(card->driver));
 398        strncpy(card->shortname, "BCD2000", sizeof(card->shortname));
 399        usb_make_path(bcd2k->dev, usb_path, sizeof(usb_path));
 400        snprintf(bcd2k->card->longname, sizeof(bcd2k->card->longname),
 401                    "Behringer BCD2000 at %s",
 402                        usb_path);
 403
 404        err = bcd2000_init_midi(bcd2k);
 405        if (err < 0)
 406                goto probe_error;
 407
 408        err = snd_card_register(card);
 409        if (err < 0)
 410                goto probe_error;
 411
 412        usb_set_intfdata(interface, bcd2k);
 413        set_bit(card_index, devices_used);
 414
 415        mutex_unlock(&devices_mutex);
 416        return 0;
 417
 418probe_error:
 419        dev_info(&bcd2k->dev->dev, PREFIX "error during probing");
 420        bcd2000_free_usb_related_resources(bcd2k, interface);
 421        snd_card_free(card);
 422        mutex_unlock(&devices_mutex);
 423        return err;
 424}
 425
 426static void bcd2000_disconnect(struct usb_interface *interface)
 427{
 428        struct bcd2000 *bcd2k = usb_get_intfdata(interface);
 429
 430        if (!bcd2k)
 431                return;
 432
 433        mutex_lock(&devices_mutex);
 434
 435        /* make sure that userspace cannot create new requests */
 436        snd_card_disconnect(bcd2k->card);
 437
 438        bcd2000_free_usb_related_resources(bcd2k, interface);
 439
 440        clear_bit(bcd2k->card_index, devices_used);
 441
 442        snd_card_free_when_closed(bcd2k->card);
 443
 444        mutex_unlock(&devices_mutex);
 445}
 446
 447static struct usb_driver bcd2000_driver = {
 448        .name =         "snd-bcd2000",
 449        .probe =        bcd2000_probe,
 450        .disconnect =   bcd2000_disconnect,
 451        .id_table =     id_table,
 452};
 453
 454module_usb_driver(bcd2000_driver);
 455
 456MODULE_DEVICE_TABLE(usb, id_table);
 457MODULE_AUTHOR("Mario Kicherer, dev@kicherer.org");
 458MODULE_DESCRIPTION("Behringer BCD2000 driver");
 459MODULE_LICENSE("GPL");
 460